Shaving device



Nov. 23, 1943 G. DALKZOWITZ 2,334,995

SHAVING DEVICE Filed June 2, 1938 4 Sheets-Sheet 1 INVENTOR Godfrey Dalkovvfiz ATTORNEYS Nov. 23', 1943. owrj'z I 2,334,995

SHAVING DEVICE Filed June 2, 1938 4 Sheets-Sheet 2 INVENTOR God fray Dad kowiiz ATTORNEYS Nov. 23, 1943.

G. DALKOWITZ SHAVING DEVICE Filed June 2, 1938 4 Sheets-Sheet 4 INVENTOR God fre Do ulkowi fz MW ATTORNEYS Patented Nov. 23, 1943 UNITED STATES PATENT FFICE SHAVING DEVICE Godfrey Dalkowitz, Brooklyn, N. Y., assignor to American Safety Razor Corporation, Brooklyn,

N.Y., a corporation of Virginia Application June 2, 1938, Serial No. 211,319

18 Claims.

This invention relates generally to shaving imeration and manufacture.

Among the more particular objects of my invention is the provision in a dry shaver of coacting cutting edges, contoured substantially in the form of similar. coaxial spirals that pass over each other with an oscillatory relative movement.

These objects and such other objects as will hereinafter appear or be pointed out are attained by the illustrative embodiments of my invention shown in the drawings, in which:

Figure 1' is a fragmentary view that is partly a front elevation and partly a medial, longitudinal section of a dry shaver head according to my invention.

Figure 2 is a fragmentary view of the shear plate and the cutter of the embodiment in Figure 1 in developed form; and

Figure 3 is a transverse sectional view through the dry shaver head of Figure 1, substantially on the line 3-4 of Figures 1 and 2, looking in the direction of the arrows, except that the section through shaft 26 is taken in a plane passing through the crank 50;

Figure 4! is a longitudinal sectional view, with portions broken away, of another embodiment of my invention;

Figure 5 is a developed view of the cutting edges of the cutter of the embodiment of Figure 4;

Figure 6 is a sectional view substantially on the line 66 of Figure 5, looking in the direction of the arrows.

Figure 7 is a transverse sectional view taken substantially on the line l'| of Figure 8 and shows a further embodiment of my invention;

Figure 8 is a longitudinal sectional view substantially on line 88 of Figure 7, looking in the direction of the arrows;

Figure 9 is a view similar to Figure 2, and illustrates a modified form of shear plate;

Figure 10 is a view similar to Figures 2 and 9 and illustrates still another shear-plate form;

Figure 11 is a transverse sectional view substantially on the line li-ll of Figure 12, and

carried b'y a., block 28, as indicated at 30.

- looking in the direction of the arrows, through a dry shaver head illustrating afurther embodiment of my invention;

Figure 12 is a fragmentary longitudinal section view, through the dry shaver head of Figure 11, substantially on the line l2|2 thereof, and looking in the direction of the arrows;

Figure 13 is a fragmentary longitudnal sectional view through the head and casing of a dry shaver, and shows power transmission mechanism whereby power from the rotary drive shaft of a motor may be converted into an oscillatory movement of the cutterof a dry shaver head;.

and

Figure 14 is a view similar to Figure 13, showing another form of power transmission mechanism.

In Figures 1, 2 and 3 of the drawings I 0 denotes the shear plate, of one embodiment of the invention. Its inner surface is a segment of a cylinder so that a cutter l2 having an outer cylindrical surface of the same radius may maintain sliding contact therewith. The shear plate is shown as traversed by slots H the side walls of which are of helical or spiral contour. Between the slots and constituting the actual body of the shear plate are the bars 16, having cutting edges I8 and 20 formed at the meeting points of their sides with their inner surfaces.

Obviously the shear plate should be of a material that will satisfactorily perform the cutting function, and I have found various ferrous alloys satisfactory for this purpose. By way of example I have also indicated the shear plate, as made of sheet material and as provided with side pieces or legs 22 by means of which theshear plate may be mounted in any suitable or preferred manner on a blok 24 that constitutes the base of the shaver head. Within the enclosed space formed by these parts is positioned the aforementioned cutter l2, which is shown as mounted on a rock shaft 26 journalled in bearings The block 28 is slidable in the space between the side pieces 22 of the shear plate It and end walls 32 carried by 24. In order to urge the block 28 and with it the cutter 12 against the shear plate l0, so as to maintain-them in contact, which is a condition necessary for the satisfactory operation of the dry shaverfiI have shown, by way of example, coil springs 38, nested in recesses 34 of the block and recesses 360i block 28.

In the embodiment of Fig. Ithe movable cutter I2 is shown as slidably mountedon block 28 and this block is urged upward so as to press the cutter against the shear plate by an arrangement comprising springs 36.

The cutter I2 is shown as provided with cutting edges 40 and 42 formed on the side walls of ribs 44 carried on the cylinder wall 46 of the cutter, and separated from each other by grooves 46. The cutting edges 46 and 42 are also spirally contoured and the pitch of their spirals are identical with those of the cutting edges I6 and 26 of the shear-plate.

In order to effect the cutting operation by the interaction of thecutting edges of the shear plate and the cutter, I have shown means comprising an arm 60 carried by the rock-shaft 26, this arm being provided with a slot 62 into which projects a ball 64 carried by a wrist-pin 66 positioned on the end of a drive shaft 56. The latter may be rotated by any suitable or preferred power means, such as the electric motor customarily housed in the handle of the modern commercial dry shavers.

Since the cutting edges I8 and 26 and the cutting edges 40 and 42 are of similar spiral contour,

' it follows that if the cutter is oscillated to a sufflcient extent in one direction the edges I6 and 42 will meet in a clipping action, and these edges meet simultaneously at all points thereof due to the identical pitch of the spirals on which they are formed. However it will be observed that the out has a strong slicing component in it due to the inclination of the cutting edges to the direction of relative motion. Similarly, when the cutter is oscillated to a .suiflcient extent in the opposite direction, the cutting edges 20 and 40 again meet in a clipping action.

In'the illustrative embodiment of Figures 1 to 3 I have shown the ribs and bars and the grooves and slotsof the cutter and shear plate respectively of the same width, and the cutter is shown in its mid-position, so that the ribs of the cutter are covered by the bars of the shear-plate. This construction, while not necessary in the practice of my invention, is convenient in that the cutting edges of the cutter need only traverse the width of the slots I4 in order to eifect a cut, and the amplitude of oscillation of the cutter need therefore be relatively small. For that reason also the slots I4 and grooves 46 are shown of less width than the bars I2 or ribs 44.

Since the slots I4 and grooves 48 must receive the hairs in order that clipping thereof I may take place, it is obviously disadvantageous from this standpoint to reduce the width of the grooves because a narrower groove can receive fewer hairs than a wide one. However, since the slot width must necessarily be small both from the aforementioned considerations and the circumstances that narrow grooves prevent the entry of flesh between the cutting edges ahd keep the hairs in position before and during the clipping action, I have added a compensating feature to my dry shaver in the form of guard plates 66 positioned at both sides of the shaver head and having slots 62 therein in registration with the slots I4 of the shear-plate. may be of the same width or of less width than the slots I4, but their outer portions are flared outwardly, whereby they will, between them, receivepractically all of the hairs encountered, and will guide them smoothly into slots I4.

It will be observed that the slots I4 of the shear plate are shown as extending into the legs 22 to a depth suflicient to admit hairs'of considerable length, and which depth exceeds by many times The inner portions of the slots 62 the thickness of the shear plate as illustrated. The slots 62 of the guard shoes are shown as of corresponding depth.

Openings 64 and 66 have been shown in the guard plate 62 and legs 22 respectively whereby shaving waste entering the shaver head may pass outwardly without clogging the shaver parts. In order to prevent the waste from entering the inner portions of the head I have further shown the block 28 as provided with walls 68 that run into close engagement with the rock-shaft 26 and that have their upper surfaces sloping downward and merging with the lower surfaces of the openings 64 and 66.

While I have shown the guards or shoes 66 as separate pieces, it is obvious that they may be made integral with other portions, such as the legs 22, and the block 24, and similarly the shear plate might be made an integral part of the block 24. However the advantages of the illustrated construction have been pointed out.

Where the shear plate is made of material other than the sheet material described, it need not be made of uniform thickness as shown in Figure 1. advantage to have different portions thereof of different thicknesses. For example the medial portion, transversely considered, may be made extremely thin, so as to bring the cutting edges as close to the flesh as possible, while the lateral portions may be made thicker, so as to provide the necessary strength. According to one practical embodiment, the inner surface of the shear-plate may be a segment of a cylindrical surface, while its outer surface may also be a segment of a cylindrical surface, but formed on a larger radius than the inner surface, and eccentric thereto.

A second embodiment of my invention, which is in the main similar to the first embodiment but differs therefrom in the details of construction is shown in Figures 4, 5 and 6. In these figures II6 denotes the shear-plate which may be of the sametype as that of the first embodiment, and may be similarly mounted. Underneath the shear plate and in sliding contact therewith is a cutter H2 carried by a rock-shaft I26 that may be mounted similarly to the rock-shaft '26 of the first embodiment, and the details of which it is therefore unnecessary to describe.

60 Adjacent each end thereof the rock-shaft I26 is shown as provided with a slotted arm I56 into the slot I6I of which extends a crank pin I 54 carried by a shaft I56, rotated in any suitable or preferred manner, as by the bevel gears I66 and I62, from the drive shaft I68.

In Figures 5 and 6 I have illustrated the detailed construction of the teeth of the cutter II2. It will be observed on viewing said figures that the teeth are shown as in the form of spirally contoured bars I66 (shown as straight bars in the developed viewof Figure 5) separated by slots I62 and held together at their ends by longitudinally extending members I66. Each bar I60 is provided at the meeting of its outer and side walls with cutting teeth I66 and "II. In this construction the slots I62 permit the shaving waste to pass from the cutting zone through the cutter, whereas in the first embodiment the On the contrary it may be found of stationary member or shear plate.

60 sector. While I do not intend to restrict myself to such limits, I have found that by making the segments of cutters between these limits, 8. highly satisfactory practical construction results.

In the further embodiment of Figures 7 and 8 I have shown a yoke 220 mounted for oscillation about trunnions 222 journalled in the casing 236 and actuated by a crank 224 carried by a rotating drive shaft 226 slidable in the slot 226 pro: vided on the yoke. A pin 230 is shown as projecting from each trunnion 222 and as having its end fitting into an opening or slot 232 provided in a slotted cutter plate 234, which is shaped so as to contact with the inner wall of an arched shear plate forming part of the casing 236, this shear plate having its inner surface constituting a portion of a cylinder. A coiled compression spring 23l is shown as positioned on each pin 230, and as abutting against the trunnion 222 at one end and against the cutter plate at its other end, so as to press the cutter plate 234 against the shear platem The shear plate proper is constituted by ribs 231 having slots 238 between each pair of ribs and the cutter is similarly constituted by ribs 240 having slots 242 intermediate each pair of ribs. The cutting edges are formed on both side walls a of the ribs and as the cutter is oscillated the respective cutting edges of the cutter and the shear plate eflect a cutting action as in the other embodiments heretofore described. It will be understood that other features mentioned in the preceding embodiments and not in connection with this embodiment may also be incorporated therein.

In Figure 9 I have shown a further embodiment of my invention in which instead of stationary and movable cutters along similarly pitched spirals, I have two sets of spiral cutters on both the movable and stationary member separated by a solid intermediate portion, one set on the movable cutter being pitched similarly to and parallel to, the corresponding set on the stationary cutter, and the other set being similarly related to the second set on the stationary cutter. Upon viewing this figure of the drawings, it will be observed that at 30l I show one set of spiral cutters on the stationary member, and at 302, show another set with the solid portion 303 therebetween and directed longitudinally of said It will be observed that while the cutters comprising each set are similarly pitched, the cutters of one set are pitched at an angle to that of the other.

The movable cutter is also similarly provided -I may further provide cutting edges on the 'end walls of the slots both of the stationary and of the movable cutter, and these edges are indicated at 3l0 and 3 on the fixed cutter and at H2 and 3l3 on the movable cutter. By suitably dimensioning the parts and regulating the throw of the movable cutters these additional cutting edges may be made to interact with each other .as well as with the spiral edges to effect the tions the teeth of which are similar to the teeth of the respective sections 01' the shear, plate and the sections are separated by a solid portion 401. The ribs oi the cutter underlying the ribs 40l, and which are numbered 405, are of the same width and pitched identically with the said ribs 4M, and the same is true oi the ribs 406 in relation to the ribs 402 of the stationary cutter.

By an arrangement such as Just described the two sides will serve for the attainment of different shaving efiects. To obtain this result it is not necessary that the ribs of the two sections be pitched in opposite directions as shown. The direction of pitch might be the same, but the amount of pitch different. p

In Figures 11 and 121s shown an arrangement in which instead of the cutter. being movably mounted on the base block the cutter is fixedly mounted and the shear plateis movable and means are provided for urging the shear plate into contact with the cutter.

The particular means illustrated in Figures 11 and 12 for attaining this result comprises a base block 502 within which is mounted for oscillation a rock shaft 504 carrying the cutter 506 provided with teeth 506, and oscillation may be imparted to a shaft 504 by a pivoted lever 5l0 provided withtwo sets of cutters 305 and 306 each pitched similarly, that is, the cutters in each set being pitched similarly with reference to each other, but at an angle with reference to the other set, and so that the cutters of the set 305 are pitched parallel to the cutters of the set 30| of the shear plate 6 downward. The shear plate 526 pro-,

plate, and so also the cutters of the set 306 are with rack teeth 5|2 engaging the pinion 6l4.

Slidably mounted on the block 502 is a structure comprising a pair of plates 5l6, having an opening 5l8 therein into which may project an'extension 520 of the block 502. A pair of coil springs 522 are shown as mounted on pins 524 projecting from the lower wall of the opening 6 l 6 and the upper ends of these springs are shown as extending into recesses in the lower wall of the projecting portion 520. The springs 522 are under compression and as a result they urge the vided with teeth 528 is mounted on the end plates H8 and an end plate 530 is shown as covering up the opening in the plates'5l6.

It will be understood that the construction shown may be used-with any of the tooth forms and mechanisms heretofore described.

In Figures 13 and 14 I have shown transmission mechanism by which the rotary movement derived from a type of motor at present used in modern commercial dry shavers may be converted into an oscillating movement suitable for the operation of shaver heads such as described hereinabove.

In Figure 13 602 indicates the rotor and 604 the rotor shaft of a motor positioned within the casing 606 of a dry shaver of conventional form.

It will be observed that the rotor shaft 604 runs transversely through the casing and carries on its end an eccentric pin 608. This pin serves to move a link M0, the other end of which is connected by any suitable or preferred mechanism 612 to the short arm 6 of "a bell crank lever pivoted at 6 I 5, the long arm SIG of which is pro-,

vided with rack teeth 6I8 that engage the teeth of a pinion 62!! carried by the movable cutter 01 a shaver head 622.

A second form of transmission is shown in Figure 14 in which I02 is the rotor and I04 the rotor shaft of a motor mounted in the casing I06. The rotor shaft carries a crank pin I08 that actuates a link H the motion of which, through mechanism H2, is transmitted to the arm Ill of a bell crank lever pivoted at H5, the other arm 'IIG of whichserves to actuate one end of a lever H5 pivoted at I20, as by thepin and slot connection shown at I22. The other end of the lever H8 is provided with rack teeth I24 adapted to' engage the teeth of a pinion I26 carried by the movable Y cutter of the shaving head 128.

It is to be observed that the mechanism shown in Figures 13 and 14 is adapted for use in connection with'any of the tooth forms shown hereinabove.

While I have herein disclosed several embodiments of my invention it will be understood that the same may be embodied in many other forms, as will be obvious to those skilled in the art, without departing from the spirit thereof, and that the disclosure herein is intended to be by way of illustration merely, and is not to be interpreted in a limiting sense, and that I do not limit myself other than-as called for by the prior art.

Having thus described my invention and illustrated its use, what I claim as new and desire to secureby Letters Patent, is:

1. A dry shaver having a pair of relatively movable cooperating cutting edges, said edges being segments of similar coaxial spirals, said edges being alternatively movable into and out of contact with each other by an oscillatory movement about the axis of said spirals, whereby said cutting edges will be caused to meet simultaneously at all points along their length.

2. In a dry shaver, an arched shear-plate hav ing its inner wall curved cylindrically, a cutter having its outer surface complementary to said cylindrical inner wall of said shear-plate, a

mounting for said cutter whereby its outer surface is held in sliding engagement to the inner surface of said shear-plate, said shear-plate com.- prising similar spiral bars spaced from each other by spiral slots, spiral cutting edges formed at the meeting point of the side walls of said bars with the inner surface of said shear-plate, spiral ribs, of the same pitch as the spiral bars. in the shear-plate, in the outer surface of the cylindrical cutter, said bars having spiral cutting edges of the same pitch as the cutting edges of contact each other simultaneously at all points thereof. I

5. A hollow shaver head having a shear-plate on its upper face, a member slidably mounted in the hollow of said shaver head, a cutter mounted for oscillation in said member, said shear-plate and said cutter having complementary contacting cylindrical surfaces, spiral slots in said shearplate having cutting teeth formed on their walls, means for keeping said surfaces in contact, discharge openings in the side walls of said shaver head for discharging shaving waste, said member being provided with an upper surface that forms a portion of the bottom wall of a continuous passage for leading said shaving waste to a discharge opening.

6. A hollow shaver head having a shear-plate on one side thereof, a member slidably mounted in the hollow of said shaver head, a cutter mounted for oscillation in said member, said shear-plate and said cutter having complementary contacting cylindrical surfaces, spiral slots in said shear-plate having cutting teeth formed on their walls, means for keeping said surfaces in contact, discharge openings in the sides of said shaver head for discharging waste, and said member having an upper surface inclined outwardly so as to conduct shaving waste toward said discharge openings.

7. In a dry shaver, an arched shear-plate supported on lateral walls, said shear plate and walls being formed from a single piece of sheet metal, spiral slots in said shear-plate, said slots extending into said walls to a depth several times the thickness of the shear-plate, and guard shoes laterally positioned in relation to said shear-plate and secured to said lateral walls and having spiral slots therein that are a continuation of the spiral slots of the shear-plate, and are of substantially the same depthias the extensions of said slots in said walls.

8 In a dry shaver, a cutting member having two rows of cutting teeth, the teeth of one row being portions of similar coaxial spirals arranged in spaced relation, and the teeth of the other row also being portions of similar coaxial spirals arranged in spaced parallel relation, but the teeth of the first row being pitched in a direction opposite to the teeth of the second row, a second cutting member having two rows of cutting teeth, the teeth of one row of said second cutting member being contoured and pitched similarly to the teeth of one of the rows of said first cutting member and being positioned for cooperation therewith in a cutting action, and the teeth of the other row of said second cutting member being contoured and pitched similarly to the teeth of the other row of said first cutting member and positioned for cooperation therewith in a cutting action, said cutting members being oscillatable relatively to each other about the axis of the spirals so that the cutting edges of both rows of said respective cutting members meet in a clipping action, said meeting being simultaneous 'along all portions of the coacting edges where said edges are similar spirals, and being at a progressively shifting point where said coacting edges are oppositely pitched.

9. In a dry shaver head, a cutter mounted for oscillation about an axis, said cutter having a cylindrical outer surface provided with similar spiral cutting teeth, a shear plate provided with spiral cutting teeth pitched similarly to the teeth of the cutter and having its inner surface contoured complementarily to the outer surface of the cutter, and yieldable means for maintaining contact between said outer surface of the cutter and said inner surface of the shear-plate.

10. In a dry shaver head, a cutter mounted for oscillation, said cutter having a cylindrical outer surface provided with similar spiral cutting teeth, a shear plate provided with spiral cutting teeth pitched similarly to the teeth of the cutter and having its inner surface contoured complementarily to the outer surface of the cutter, and means for maintaining contact between said outer surface of the cutter and said inner surface of the shear-plate, said means being in the form of a slldable member within which the cutter is mounted, and resilient means for urging said' member in a direction to maintain said contact.

11. For driving a dry shaver head having a shear plate and a cutter mounted for oscillation in said head, toothed means carried by said cutter for imparting oscillation thereto, pivotally mounted toothed means for meshing with said first toothed means, a rotary motor, and means intermediate said motor and said pivotally mounted toothed means for converting the rotary movement of the motor into an oscillating movement of said pivotall mounted toothed means.

12. For driving a dry shaver head having a shear plate and a cutter mounted for oscillation in said head, toothed means carried by said cutter for imparting oscillation thereto, a bell crank having one of its arms provided with teeth adapted to engage said toothed means, a rotary motor having this axis of its rotor disposed in a plane parallel but spaced from the axis of oscillation of said cutter, and means intermediate said motor and the other arm of said bell crank for converting the rotary movement of the motor into an oscillating movement of said pivotally mounted toothed means.

13. For driving a dry shaver head having a shear plate and a cutter mounted for oscillation in said head, toothed means carried by said outter for imparting oscillation thereto, a pivotally mounted lever having teeth thereon for meshing with said toothed means, a rotary motor, and means intermediate said motor and said pivotally mounted toothed means for converting the rotary movement of the motor into an oscillating movement of said pivotally mounted toothed means.

14. In a dry shaver, an arched shear-plate supported on lateral walls, said shear-plate and walls being formed from a single piece of sheet metal, spiral grooves in said shear-plate provided with cutting teeth on their edges, guard shoes positioned laterally of the walls of said shearplate and having spiral slots therein that are a continuation of the spiral grooves of the shearplate, a block mounted for sliding movement between said walls, openings in said lateral walls and said guard shoes for the discharge of waste,

said block having its top walls downwardly inclined from its midportion, and said openings having their bottom walls inclined and forming continuations of the top walls of said block, and a cutter provided with spiral grooves similarly pitched to the spiral slots of the shear-plate and having cutting teeth on the edges of its slots adapted to coact with the cutting of the shearplate in a cutting action, said cutter being mounted for oscillation in said block, said cutter being oscillatable so that its teeth alternately move into and out of contact with the teeth of the shearplate, and means acting on said block for urging said cutter against said shear-plate.

15. In a dry shaver head, a cutter having a cylindrical outer surface, said cutter being mounted'for oscillation about its cylindrical axis, said outer surface being provided with spiral cutting teeth arranged in sections, each section having cutting characteristics determined by a construction comprising similar spiral ribs spaced from each other by spiral slots, and the cutting characteristics of each section being different from that of the other sections.

16. In a dry shaver head, a shear-plate comprising two sections provided with cutting edges, the cutting characteristics of each section being determined by its construction which comprises similar spiral ribs uniformly spaced from each other by spiral slots and said cutting teeth being formed on the edges of said ribs, and the cutting characteristics of one section being different from the cutting characteristics 01' the other section.

1'7. In a shear-head, a stationary cutter com-- prising a series of rows of arcuate-shaped cutter bars having a perforatory slot on each side of each cutter bar, the width of each of the perforatory slots being substantially greater than the width of said cutter bars, said cutter bars and slots extending over substantially the entire length of said cutter, the bars and slots of each adjacent pair of rows thereof being inclined oppositely relative to the long axis of said shear head, there being an even number of such rows of cutter bars whereby the extreme outside perforatory slots on opposite edges of the shear head are inclined in opposite directions, all of said cutter bars lying substantially in a common uniform arcuate surface, and vertically extending perforatory slots in the sides of the cutter formed and adapted to communicate with the angular slots in the face of said cutter positioned adjacent the side edges thereof.

18. In a dry shaver, a cutting member having two rows of cutting teeth, inclined relative to the longitudinal axis of said cutting teeth, the

teeth of the first row being pitched in a direction opposite to the teeth of the second row, a second cutting member having two rows of cutting teeth,

the teeth of one row of said second cutting member being inclined and pitched similarly to the teeth of one of the rows of said first cutting memher and being positioned for cooperation therewith in a cutting action, and the teeth of the other row of said second cutting member being inclined and pitched similarly to the teeth of the other row of said first cutting member and posttioned for cooperation therewith in a cutting action, said cutting members being oscillatable relatively to each other.

GODFREY DALKOWITZ. 

